EXERGETIC ANALYSIS OF A SOLAR ABSORPTION MACHINE

Absorption refrigeration machines need energy for their proper functioning. Much of this energy is lost due to energy dissipation by friction or during heat transfer under temperature difference. But thanks to the various methods of existing thermodynamic analyses of entropy and exergy, the energy losses at the various nodes of the absorption refrigeration machines can be investigated, then minimized in order to improve the performances. In this paper, the specific entropy, the dissipated energy (non-dimensional entropy generation), as well as the loss of exergy at the different elements of the solar absorption machine were calculated and analysed as well as the exergy efficiency of the system. The results give information on the actual weaknesses a solar absorption machine having a nominal cooling capacity of 10 kW. It was found that the generator is the most energy-dissipating component with 44.16% (meaning 4.30 W/K), followed by the absorber with 37.58% (3.66 W/K). The greatest loss of exergy is obtained at the generator with 28.50%, followed by the heat exchanger with 28.48% of the total loss of exergy.